The chemical composition of the essential oil obtained by hydrodistillation from the aerial parts of Hyptis verticillata Jacq. was elucidated by a combination of GC and GC-MS analyses. The oil was dominated by the sesquiterpenoids cadina-4,10(15)-dien-3-one (15.1%) (1) and aromadendr-1 (10)en-9-one (squamulosone) (30.7%) (2). The oil exhibited chemosterilant activities against the cattle tick, Boophilus microplus Canest., and toxic action against adult Cylas formicarius elegantulus Summer, the most destructive pest of sweet potato (lpomoea species).....read more